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Being driven by an external electric field a polaron carrying both spin 1/2 and charge ±e moves at a constant speed in a polymer chain. When the polaron passes through a specific site, which couples to a magnetic impurity via spin-exchange interactions, its spin undergoes a spin-flip process if it is antiparallel to the impurity spin. Our numerical simulation shows that (a) a swap-like operation is performed between the polaron and impurity during the scattering process (b) polarons might be good candidates to be information carriers in the molecular scale. 相似文献
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对于含有两个杂质的一维单原子链的振动方程求解,得到晶格振动频率的解.分析了振动频率和杂质质量以及两杂质间距离的关系. 相似文献
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Aligned Elongation of Ag Nanoparticles Embedded in Silica Irradiated with High Energy Ni Ions 下载免费PDF全文
Metallic nanoparticle(NP) shapes have a significant influence on the property of composite embedded with metallic NPs. Swift heavy ion irradiation is an effective way to modify shapes of metallic NPs embedded in an amorphous matrix. We investigate the shape deformation of AgNPs with irradiation fluence, and 357 MeV Ni ions are used to irradiate the silica containing AgNPs, which are prepared by ion implantation and vacuum annealing. The UV-vis results show that the surface plasmon resonance(SPR) peak from AgNPs shifts from 400 to 377 nm. The SPR peak has a significant shift at fluence lower than 1 × 10~(14) ions/cm2 and shows less shift at fluence higher than 1 × 10~(14) ions/cm~2. The TEM results reveal that the shapes of AgNPs also show significant deformation at fluence lower than 1 × 10~(14) ions/cm~2 and show less deformation at fluence higher than1 × 10~(14) ions/cm~2. The blue shift of the SPR peak is considered to be the consequence of defect production and AgNP shape deformation. Based on the thermal spike model calculation, the temperature of the silica surrounding Ag particles first increases rapidly, then the region of AgNPs close to the interface of Ag/silica is gradually heated. Therefore, the driven force of AgNPs deformation is considered as the volume expansion of the first heated silica layer surrounding AgNPs. 相似文献
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理论上研究了含stubs的Rashba自旋轨道耦合(spin-orbit coupling, SOC)量子波导系统的自旋极化输运性质. 利用晶格格林函数方法,发现由于stubs和SOC产生的势阱使系统中出现束缚态,这些束缚态与传播态之间相互干涉导致电导中出现Fano共振结构,同时在对应的自旋极化率中也出现Fano共振或反共振结构. 此外,由于系统结构的突变使电子被反向散射和量子干涉效应,电导中出现一系列的共振峰. 但是,当系统加上外磁场后,所有这些效应都被抑制, 系统重新出现量子化电导, 同时自旋电导也出
关键词:
量子波导
自旋极化输运
自旋轨道耦合 相似文献
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The local sine-Gordon model with two frequencies is studied by a variational method.The renormalization mass and classical field path are calculated.We find an Ising-like phase transition,which is analogous in the global sine-Gordon model with two frequencies.A full phase diagram is given. 相似文献
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Scaling Properties of Energy Gap in Dimerized Spinless Fermion Chains with Quasiperiodic Modulation 下载免费PDF全文
By employing the exact diagonalization method, we investigate the low-energy benavlour ot the almenzed spinless fermion chains with quasiperiodic modulation. It is found that for off-diagonal modulation, the energy gap with length N scales as exp(-cN^ω) with nonuniversal exponent ω if the dimerization is nonzero. However, for diagonal modulation, there may exist a critical dimerization δc beyond which the system exhibits a metal-insulator transition. 相似文献
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在平均场理论基础上,研究了具有DzyaloshinskiiMoriya(缩写为DM)相互作用的二维spinPeierls模型以及DM相互作用对二聚化的影响.研究表明,随模型参量的不同,DM相互作用能加强或削弱二聚化位移.另外,发现DM相互作用对二聚化位移的依赖程度参量λ存在一个特殊点λc,当λ=λc时,DM相互作用对二聚化没有影响.随晶格弹性系数的增加,λc将增大,而链间耦合将使λc减小
关键词:
二维spinPeierls模型 DM相互作用 相似文献
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